Polysaccharides, especially antigenic polysaccharides, are used in preparation of vaccines. Monovalent, divalent and poly (multi) valent vaccines containing one, two or more polysaccharides are available in the market for preventions of certain diseases or infections caused by various microorganisms. The multivalent polysaccharide vaccines have been licensed for many years and have proved valuable in preventing diseases such as Pneumococcal, Meningococcal or Haemophilus influenzae diseases. Surveillance data gathered in the years following Prevnar's introduction has clearly demonstrated a reduction of invasive pneumococcal disease in US infants as expected [1, 2]. Despite of several studies carried out on these polysaccharides, a need for improving yields as well as quality (purity) of the polysaccharides always exist in the industry (e.g. Hib, MenC).
Prior inventions, for e.g. EP00024 disclosed methods involving the use of toxic components like Phenol; organic solvents like isopropanol or ethanol; use of detergents like CTAB for polysaccharide precipitation and the use of sodium acetate for pH adjustments.
EP 497525 disclosed a method involving thermal hydrolysis and use of sodium acetate to hydrolyze the sample.
CA 1206905 described a method which uses toxic organic solvents like Phenol, butanol, Toluene and chloroform and also involves use of detergent cetavlon (CTAB).
U.S. Pat. No. 4,242,501 and some more studies [5] mention a method which involves serotype specific anion exchange chromatography.
Classical methods described by Institut Merieux give details of the use of CTAB and protease [6] for purification of N. Meningitidis serogroup A, C polysaccharide purification [7].
Some other methods made use of proteinase for removal of proteins and use of lectin agarose columns resulting in high costs and process which can't be scaled up easily [8, 9].
US 20060228380 as well as some studies [10, 11] disclosed a method which comprises CTAB for polysaccharide (Ps) precipitation, carbon filter for nucleic acid removal and potassium iodide for precipitation of CTAB.
U.S. Pat. No. 5,847,112 disclosed a method which makes use of multiple isopropyl alcohol and cetavlon for the precipitation of PS [12].
The prior art methods can not be applied to all PS for purification since Pneumo Serotypes 7F, 33F and 18C can not be precipitated using CTAB while the remaining serotypes can be precipitated.
Also the prior art methods are multi-step and therefore are tedious and non-scalable.
The present invention aims to present an easily scalable, efficient and fewer steps purification process that eliminates the use of any toxic component, organic solvent and/or detergents. The significant finding of this invention is applicable to purification of all capsular polysaccharides.